Door drive system

ABSTRACT

The invention relates to a door drive system for a wing of a door, a window or similar, comprising a housing with a drive and/or return device, e.g. a closing spring ( 7 ), and a preferably hydraulic damping device. In practice, drive housings of this type are cast in aluminium. The production costs are relatively high since housing openings and boreholes such as hydraulic channels have to be cut into the housing ( 31 ) later on. According to the invention, the housing ( 31 ) is produced wholly or partly from plastic. This enables the cavities which are necessary for the housing to function, such as housing boreholes and/or openings to be made in the drive housing when it is produced, without removing material by cutting. According to another design, the drive housing has several housing parts which are produced separately. The adjacent sections of the housing parts are then stuck or welded together. Housing boreholes such as hydraulic channels can be made in the adjacent surfaces of the housing parts which are shaped accordingly, without removing material by cutting.

BACKGROUND AND SUMMARY OF THE INVENTION

The invention relates to a door closer and to a method for themanufacture of a door closer.

Door closers are known which have closing springs as energy accumulatorsand a hydraulically damped closing movement, in which the closing springcooperates with a hydraulic piston-and-cylinder unit. Thepiston-and-cylinder unit and the closing spring are disposed in a metalhousing and cooperate through a rack and pinion or through a cam diskdrive with a closer shaft journaled in the housing, which is connecteddirectly or through a force-transmitting articulation to the door. Whenthe door is opened manually the energy accumulator is charged andafterward discharged again in the automatic closing of the door. Uponeach opening and closing movement of the door, the action of the pistoncauses hydraulic medium to be exchanged between the two piston workingchambers through hydraulic passages disposed within the housing. A doorcloser of such construction is disclosed, for example, in EP 328 912 B1or DE 38 353 A1.

Such door closers are known in practice in various versions. There arekinds which are mounted flat on the door or on the frame, and kindswhich are integrated in the door frame. Scissor articulations or slidingarm articulations are used as the force-transmitting articulations. Thehousing of the door closer is made in practice of cast aluminum or fromaluminum extrusions. The cost of manufacture is relatively high onaccount of the necessary machining. The hydraulic passages must be boredinto the housing and the cylinder chamber must also be machine-finishedin order to assure a precise seating of the piston.

DE 195 29 168 A1 describes a hydraulic door closer which consists of anelongated one-piece housing. The housing can be made of metal or alsofrom polymer materials, and has a cylindrical longitudinal bore toaccommodate the piston and a cross bore to accommodate the closingshaft. The exchange of the hydraulic medium takes place through a valvewhich is disposed in the housing cover and extends axially into thepiston chamber and at the same time plunges into an axial bore in thepiston. The housing itself does not have any hydraulic passages.

The invention is addressed to the problem of developing a housing for adoor closer which will be easy to manufacture and machine, as well asdeveloping a method for its manufacture.

The problem is solved according to the invention by the use offiber-reinforced, preferably glass fiber- or carbon fiber-reinforcedplastic offers special advantages in regard to strength and fashioning.Finish machining can be reduced or entirely eliminated. Also,advantageous friction properties are achieved by the use of a suitablecombination of materials. Also, coatings and overlays of plastic on thehousing interior wall, e.g., on the cylinder's interior wall, or also onthe outside wall of the piston can be provided advantageously, andplastic coating on metal walls or on sandwich materials is possible.

By the use of suitable combination of materials, e.g., valves and valveseats in the housing, the desired temperature-independence of the valveadjustment can be obtained by appropriate temperature compensation ofthe materials. A combination of different plastics as well as acombination of metal and plastic can be used.

Special advantages are obtained if the plastic material is dyed to thefinal color of the door closers, so as to eliminate the need to lacqueror otherwise finish-coat the closer to the final color or to simplifyseparate external coloring operations.

In the door closer housing, bore chambers, e.g., a passage in thehousing, a mounting bore and/or space to accommodate an output member, adamping piston, a closing spring, a closing motor or a valve can bealready formed in the door closer housing, at least section-wise,without machining, when the housing is formed, or at least it can bepreformed without machining operations. Alternatively, or additionally,the formation of at least one bore chamber is performed during theassembly of several separately made housing parts, the bore chamberbeing created without machining in the contacting surfaces of thehousing parts or at least being preformed without cutting operations.

Since such bored chambers are formed while the door closer housing isbeing made by an appropriate injection mold when the door closer housingis produced, the manufacturing cost is considerably reduced. As a rule,no further machining operations are necessary. The housing is at leastpartially, but more advantageously entirely manufactured from plastic.Manufacture is performed, for example, by the injection molding method.This method also makes it possible in a single manufacturing process toinstall, for example, a shaft bearing for the output shaft by thetwo-component method.

Furthermore, it is possible by using plastic to produce the door closerhousing from a plurality of separate housing parts and simply glue orweld them together. The cylinder chamber can be closed afterinstallation of the piston and closing spring by means of an end plugwhich is welded onto the cylinder chamber. It is therefore not necessaryto form a screw thread in the cylinder chamber or on the plug.

Alternatively, the cylinder chamber can be closed by an end cap cuppedaround the cylinder chamber while hydraulic passages are formed with itsmarginal sections.

In the door closer housing, recesses can be created for separately madeinsert parts which are welded or cemented into the recesses. At the sametime, passage sections of the damping device can be formed or preformedin the confronting faces of the door closer housing and of the insert.This method is especially suited for the formation of longitudinalpassages which are brought out at the end of the housing for theinsertion of the hydraulic valves. The radial passages connecting thelongitudinal passages to the cylinder chamber are preferably alreadyformed in the housing during production of the latter, withoutmachining.

In another embodiment the door closer housing is made from two halves,in which the longitudinal halves of the cylinder chamber are formed. Atthe same time channels or channel sections of the door closer can beformed in confronting surfaces of the housing halves.

In another embodiment of the invention it is possible to make the pistonand in some cases the output shaft wholly or partially of plastic,preferably however from a plastic-metal composite material. In that casethe basic body of the piston is made from plastic, while recesses forsealing rings as well as passages for check valves can be alreadyformed. Then a rack made of metal is placed or cemented into acorresponding recess in the piston.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention is further explained in the drawings, wherein:

FIG. 1 is a schematic front elevation of an entrance with a flat-mountedsliding-arm door closer,

FIG. 2 a longitudinal section through the door closer housing in FIG. 1,

FIG. 3a) a cross section through the door closer housing, taken alongline III—III in FIG. 2 in the area of the hydraulic passages, b) a crosssection through a hydraulic passage, taken along line IIIb in FIG. 3a,

FIG. 4 a cross section through the door closer housing, taken along lineIV—IV in FIG. 2 in the area of the closer shaft,

FIG. 5 a representation corresponding to FIG. 4 with the closer shaftinstalled,

FIG. 6 a cross section through the door closer housing along line VI—VIin FIG. 2 in the area of the mounting bores,

FIG. 7 a side view of the door closer housing in FIG. 1,

FIG. 8 a longitudinal section through the door closer housing in FIG. 1,

FIG. 9 a cross section through a door closer housing of an alternativeembodiment,

FIG. 10a) a cross section through a door closer housing of anotherembodiment, b) a cross section through a hydraulic passage, along lineXb in FIG. 10a,

FIG. 11 a longitudinal section through a door closer housing accordingto a next embodiment,

FIG. 12 a longitudinal section through a door closer housing composed oftwo halves,

FIG. 13 a representation like FIG. 5 of a modified embodiment in whichthe needle bearing is fastened with a ring.

DETAILED DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a schematic front elevation of a doorway. The door 1 ispivoted at a vertical edge in hinges 11 on the door frame 2. The door 1is equipped with a flat-mounted sliding arm door closer 3.

The sliding arm door closer 3 consists of a door closer housing 31 inwhich a closer shaft 4 is mounted for rotation. A sliding arm 5 isfastened for co-rotation with the closer shaft 4 and has at its free enda slider 51 which is carried for displacement and rotation in a sliderail 52. In the door closer housing 31 there are a closing spring 7represented in FIG. 8, and a damping device, which cooperate with thecloser shaft 4. The sliding arm door closer 3 can be a conventionallyconstructed door closer 3, e.g., a hydraulic door closer such asdescribed in DE 36 38 353 A1. Such a door closer 3 operates such that,when the door 1 is opened manually, the positive movement of the linkage5 and of the closer shaft 4 thus produced, the closing spring 7 iscompressed. The closing then is performed automatically by the action ofclosing spring 7, while hydraulic medium is exchanged between two pistonworking chambers.

In the kind of installation shown in FIG. 1, known as door-mountedinstallation, the door closer housing 31 is mounted on the door 1. Inthis case the slide rail 52 is mounted on the door frame 2. In anothertype of mounting that is not shown, known as head-mounted installation,the door closer housing 31 is mounted on the door frame 2 and the sliderail 52 on the door 1. Installation can be made either on the hinge sideor on the side opposite the hinge.

In alternative embodiments, a scissors linkage can be used instead of asliding arm linkage 5. Application of the invention is also possible ontwin doors, which can additionally be equipped with a closing sequencecontrol. Also possible is the use of the invention on electrohydraulicdoor closers which additionally have a hydraulic pump for motor-drivenopening or motor-assisted opening of the door 1. The hydraulic pump ispreferably also disposed in the housing 31 or connected to it. In thefollowing figures the explanation of the various embodiments of theinvention is based on the hydraulic door closer 3 already described.

FIG. 2 shows a longitudinal section through an embodiment of a doorcloser housing 31 according to the invention. Inside of this housing 31there is formed the cylinder chamber 32 which accommodates the piston 6and the closing spring 7 shown in FIG. 8. The cylinder chamber 32 isopen at its one end, and after installation of the piston 6 and closingspring 7 it is closed, by welding for example, with the disk-shaped endplug 33 represented separately in FIG. 2. Both the door closer housing31 and the end plug 33 are made of plastic, preferably by injectionmolding.

The use of plastic offers various advantages which ultimately amount toa decided reduction of the cost of manufacture. Plastic parts can beinjection-molded or cast with substantially less tolerance compared tometal parts. Thus, right in the manufacture of the raw housing a greateraccuracy of fit can be achieved, which ultimately reduces the necessaryfinishing operations. It is also an advantage that most of the openingsand bores in the housing can be created without machining operationsright during the production of the housing 31 by the use of appropriateinjection molding dies. This eliminates the drilling of holes afterwardfor mounting or for the hydraulic system. If nevertheless finishingoperations should be necessary or desired, they can be performed muchmore easily than in a metal housing. Also, in the two-componentinjection molding process it is possible to work two different plasticsin a single manufacturing process, if it is necessary, for example, touse plastics with especially good low-friction qualities or plasticswith especially great strength. Plastics suitable for the manufacture ofthe door closer housing 31 are, for example, aromatized polyamides witha high content of glass fibers to increase strength. This material isalso distinguished by low thermal expansion, which is advantageous tothe accuracy of adjustment of the hydraulic valves.

The end plugs 33 do not have to be threaded into the housing as in thecase of conventional metal housings, but can be affixed to the housingby ultrasonic welding. First the end plug 33 is inserted into the end ofthe housing 31 in a circular recess 32 b whose diameter is greater thanthe diameter of the concentric cylinder chamber, where it covers themouth of the cylinder chamber 32 since its diameter is greater than thatof the cylinder chamber 32. With a bead 33 a formed in the radiallyouter part of the plug face, the end plug 33 lies against the area ofthe housing surrounding the cylinder chamber 32. The bead 33 a serves asan energy aiming means in ultrasonic welding. By a brief input of energythrough ultrasonic waves the bead 33 a and the adjacent housing area arebriefly fused and thereby permanently welded together.

Alternative fastening methods which can likewise be used include solventwelding wherein both of the plastic parts are welded together bytransient action of a solvent, or pinning with a number of smallfastening pins which are set radially into the housing and enter intothe plug 33.

In alternative embodiments the end plug 33 does not necessarily have tobe placed on the piston end of the cylinder chamber 32. The opposite,closing-spring end of the cylinder chamber can be closed in that manner.Likewise, both ends of the cylinder chamber 32 can be closed by endplugs 33.

In modified embodiments, a cup-shaped housing part can be providedinstead of the end plug 33, and can be bonded to the other housing partin appropriate manner.

The housing 31 in FIG. 2 has in its center a transverse cylindricalopening 34 cutting through the cylinder chamber 32 to accommodate thecloser shaft 4 represented in FIG. 5. The transverse opening 34 isformed in the housing 31 during manufacture of the latter, and does nothave to be bored after it. In like manner, four mounting bores 35passing through the housing 31 for mounting the door closer 3 on a door1 or door frame 2 are formed in the housing 31 when the latter isproduced. The transverse opening 34 and the mounting bores 35 are shownand explained in detail in FIGS. 4 to 6.

FIG. 3a shows how the hydraulic passages are formed without machining. Across section along line III—III is represented in FIG. 2. On the bottomof the housing 31 (on the right in the figure) there are two elongated,rectangular-shaped recesses running from the end of the housing near itsoutside edges. In the bottom of each recess 36, one half of alongitudinal passage 82 is formed. The two recesses 36 can havedifferent lengths, according to where the radial passages 81 branchingoff from them and represented in FIG. 3b open into the cylinder interiorspace.

Into the two recesses 36, separately made inserts 37 of plastic areinserted, in which the other half of the circular (for example)longitudinal passages 82 is formed. The insertion of the inserts 37 thuscreates the longitudinal passages 82. The inserts 37 are welded orcemented to the housing 31 as already described in the case of end plug33.

As seen in FIG. 3b, a radial passage 81 branches from both ends of eachlongitudinal passage 82 into the cylinder chamber 32. The hydraulicvalve for establishing the closure damping or abutment, which is notshown in the figure, is inserted from the end of the longitudinalpassage 82. The first radial passage 81 opens on the piston end of thecylinder chamber 32 in the area immediately before the end plug 33. Thesecond radial passage 81 opens in the middle area of the cylinderchamber 32 or in the end area of the cylinder chamber 32 according towhether it is intended to adjust the closure damping or the abutment.The radial passages 81 are formed during the production of the housing31 by means of appropriate injection molds and do not need to be boredafterward. Depending on requirements, however, it is also possible tobore the hydraulic passages into the housing 31 in a conventionalmanner.

FIG. 4 shows a section through the housing 31 in the area of thetransverse bore 34 for the closer shaft 4. Annular sealing beads 34 aare formed on the inner wall of the transverse bore 34 on both sides ofthe cylinder chamber 32. These sealing beads 34 a also consist ofplastic and are placed in the transverse bore 34 by the two-componentinjection molding process during the production of the housing 31. Bytheir sealing action the sealing beads 34 a prevent the escape ofhydraulic oil from the cylinder chamber 32. In the case of specialdesigns, the sealing beads 34 a can be configured as slide bearings forthe closer shaft 4 which is not represented.

An alternative possibility for mounting the closer shaft 4 is shown inFIG. 5. The sealing is in this case by cementing a needle bearing sleeve41 of plastic or metal or ceramic into the transverse opening 34. Insideof the cylinder chamber 32 can be seen the piston 6 and the pinion 43meshing with the rack 61.

In an embodiment different from FIG. 4, represented in FIG. 13 theneedle bearing 41 is sealed by a separate ring 410 with a sealing ring411. To accommodate the needle bearing 41 and the ring 410 thetransverse opening 34 is configured in the manner of a stepped bore, thegreater diameter being formed at the outer axial end of the transverseopening 34 and the smaller diameter being formed in the section openinginto the cylinder chamber 32. The needle bearing 41 is inserted with theneedle bearing sleeve into the section of smaller diameter and cementedtherein, and extends with about one-third of its axial length into thearea of larger diameter. The ring 410 is inserted into the transverseopening 34 in the area of larger diameter to abut against the radialstep of the transverse opening 34. The ring 410 has a first axialsection with an inwardly pointing rim and a second axial section ofsleeve-like configuration and has at its end a step-shaped recess 412 inits inner wall. The ring 410 is inserted into the transverse opening 34in the area of the greater diameter such that the end surface of thesleeve-like end abuts against the radial step of the recess 34, and thesleeve-like section of ring 410 is fitted between the inner wall of thetransverse opening 34 and the outer wall of the section of the needlesleeve 41 reaching into this area. The radial recess 412 formed in thesleeve-like section of ring 410 forms in this situation an undercutgroove of substantially U-shaped cross section. The sealing ring 411 isheld in this groove.

With the sealing ring 411 in the undercut groove a good sealing of theneedle bearing 41 is obtained. The undercut groove 412 in which thesealing ring 411 is disposed is formed by means of the separate ring 410without the need to form an undercut groove in the opening 34 in theinjection molding procedure. In the case of injection molding, such anundercut would require a complicated mold. The ring 410 can be made ofplastic or metal. It can be glued in, but also welded in by ultrasound.

Instead of a needle bearing 41 a ball bearing or other separate bearingcan be used and sealed in the same or a similar manner with a separatering. Such a seal by a separate ring or the like can be made also in thecase of other components mounted in the housing, e.g, for sealing valvesor for sealing the housing cover.

FIG. 6 shows a cross section in the area of the mounting bores 35. Themounting bores 35 are formed on both sides of the cylinder chamber whenthe door closer housing is injection molded. Thus no machining of thehousing 31 is necessary after it has been molded. The mounting bores 35run from the slightly curved front side to the rear side of the housing31, the bores having a countersink in a front-end section 35 a toaccommodate the screw heads.

FIG. 7 represents a side view of the door closer 3 when closed by an endplug 33 and provided with valves 8. One valve serves to regulate thedamping action and another serves to adjust the final closing.

FIG. 8 shows a longitudinal section through a door closer housing 31 inthe area of a piston 6 made of a plastic and metal composite. The basicbody of the piston 6 is made of plastic. This results in immediatelyimproved friction properties in the cylinder chamber 32. Moreover, therecesses for the sealing ring 62, or the passages for the check valve 85are already formed in the piston 6 when the latter is molded. The costof manufacture is considerably reduced by the elimination of machiningoperations. The rack 61 made of metal is loosely placed inside of theinjection-molded plastic piston 6, or cemented or fastened therein by asuitable method. In like manner the closer shaft 4 can also be made of aplastic and metal composite material. Alternatively it is possible tomake the pinion 43 and/or the piston 6 of metal. Furthermore it ispossible to make these components as well as the closer shaft 4 entirelyof plastic, preferably of plastics of high compressive strength.

In FIG. 9 the schematic cross section of an alternative embodiment isshown. The housing is composed of two separately made plastic halves 31a, 31 b. The longitudinal passages 82 lie in the plane of section andare formed half on each side of the cylinder chamber 32 in each half 31a, 31 b. The housing halves 31 a, 31 b, can be assembled together alongthe longitudinal axis of the housing, i.e., the plane of separation orsection runs lengthwise of the housing.

FIG. 10 shows another embodiment in which the longitudinal passages 82are formed in the housing 31 when the latter is made. In this embodimentseparate inserts 37 are not used. To be able to form also the radialpassages 81 when the housing 31 is molded instead of by machining theyare formed as shown in FIG. 10b by-leading them into the longitudinalpassage 82 and out to the bottom 31 c of the housing. This is necessary,since the injection molding tools enter from the outside. The radialpassages 81 are afterwards sealed at the bottom 31 c of the housing.

FIG. 11 shows another embodiment in longitudinal section. In thisembodiment the cylinder chamber 32 is not closed by an end plug 33 butby an end cap 38 of U-shaped cross section, the end cap 38 being cuppedaround the housing 31 with the formation of longitudinal passages 82.The end cap 38 has a first short marginal section 38 b and a second,longer marginal section 38 b. So it can be of a cup-like configurationwith marginal sections 38 a, 38 b, of different length around itscircumference. In the area of these marginal sections 38 a, 38 b, theend cap 38 overlaps the housing 31 and the cylinder chamber 32. A gapremains between the insides of the marginal sections 38 a, 38 b, and theoutside of the housing 31 and serves as a longitudinal passage 82. Theradial passages 81 leading into this gap are already formed when thehousing 31 is made. As also already described in the case of the endplug 33, the end cap 38 is also welded to the housing 31. In thisembodiment separate inserts 37 to form the longitudinal channels 82 areno longer necessary.

An additional variant embodiment with a cylinder chamber 32 consistingof two halves 31 a, 31 b, is shown in FIG. 12. The housing halves 31 a,31 b, can be put together in a plane across the longitudinal axis of thehousing, i.e., the plane of the seam or section runs transversely acrossthe housing.

In a first half 31 a formed in the axial direction of the cylinder 32the piston is guided for axial displacement as in the embodiment in FIG.8. This first cylinder half 31 ahas no cylinder cover but only acylinder opening 32 a against which the second cylinder half 31 b isplaced with its corresponding cylinder opening 32 a. In the secondcylinder half 31 b, which is cup-shaped as is cylinder half 31 a, thespring, not shown, is contained with its essential length. In contrastto FIG. 11 the cylinder halves 31 a, 31 b, do not overlap one anotherbut form a seam 31 d as a plane of section in which they are welded orcemented together. The position of the seam 31 d is chosen such that thepiston 6 does not come in contact with the seam 31 d in any of thepiston's possible positions, and the seam 31 d is situated exclusivelywithin the spring chamber.

The use of the invention is not limited to the door closer 3represented. Basically its use is advantageous where metal housings areused in door closers on doors, windows, smoke exhaust openings, lightcupolas and the like, which heretofore have had to be expensively madeby machining for their purpose.

What is claimed is:
 1. A closer for a door, comprising: a housingcomprising at least one bore chamber, wherein at least one section ofthe housing is made of plastic; a restoring device, disposed in thehousing, which is charged upon movement of the door and serves as anenergy accumulator for automatic closing of the door; a damping devicedisposed in the housing for damping at least one of closing or openingmovement of the door; an output member, received in the housing, onwhich the restoring device acts, a force-transmitting linkage that issupported at one end in a rotary or sliding bearing and at the other endis connected to the output member, and inserts received in recessesdefined in the housing so as to define passages communicating with saidat least one bore chamber for permitting passage of fluid therebycontrolling movement of said door.
 2. A closer according to claim 1,wherein the restoring device is a closing spring.
 3. A closer accordingto claim 2, wherein at least one of the output member, a damping pistonof the damping device, and the closing spring are received in the atleast one bore chamber, and wherein the at least one bore chamber isconfigured at least section-wise without machining or is preformedbetween a plurality of housing parts made of plastic without machining.4. A closer according to claim 3, wherein the piston comprises plastic,metal, or ceramic.
 5. A closer according to claim 4, wherein the pistoncomprises a plastic-metal composite material or a plastic-ceramiccomposite material.
 6. A closer according to claim 3, wherein at leastone of the output member, a rack, or an output pinion is made fromplastic, ceramic, a plastic-metal composite material, or plastic-ceramiccomposite material.
 7. A closer according to claim 6, wherein the rackis a separate part and is laid, clipped, cemented, welded or injectedinto the piston.
 8. A method for the manufacture of a closer for a door,the closer including a door closer housing, comprising: providing arestoring device, disposed in the door closer housing, that is chargedupon the movement of the door and is configured as an energy accumulatorfor automatic closing of the door, providing a damping device disposedin the door closer housing for damping closing or opening of the door,providing an output member, received in the door closer housing, onwhich the restoring device acts, providing a force-transmitting linkagewhich is supported at one end in a rotary or a sliding bearing and atthe other end is connected to the output member, and, assembling aplurality of plastic housing parts without machining to form the doorcloser housing, forming at least one bore chamber in which at least oneof the output member, a damping piston, and a closing spring can bereceived.
 9. A closer according to claim 1, wherein the damping deviceis a hydraulic damping device.
 10. A closer according to claim 1,wherein the output member is an output shaft.
 11. A closer according toclaim 10, further comprising a shaft bearing for the output shaftcemented or welded in a corresponding opening in the housing.
 12. Acloser according to claim 11, wherein the shaft bearing is a moldedplastic part.
 13. A closer according to claim 11, wherein the shaftbearing is configured as a needle bearing or ball bearing formed from aceramic.
 14. A closer according to claim 11, further comprising aseparate ring disposed in a recess for receiving the shaft bearing,wherein the separate ring comprises plastic, metal, or ceramic.
 15. Acloser according to claim 14, wherein the separate ring is adapted toreceive a separate gasket.
 16. A closer according to claim 15, whereinthe separate gasket is configured as a sealing ring which is disposed ina recess of the separate ring.
 17. A closer according to claim 15,wherein the separate ring forms, together with a radial step in therecess, an undercut groove in which the separate gasket is received. 18.A closer according to claim 1, wherein the bore chamber accommodates theclosing spring, and wherein the housing comprises at least two housingparts, each housing part defining a part cut in the axial direction ofthe cylinder chamber or a part cut transversely of the cylinder chamber.19. A closer according to claim 18, wherein the cylinder chamber isclosable at one or both ends by a separately made end plug.
 20. A closeraccording to claim 19, wherein the end plug is disk-shaped.
 21. A closeraccording to claim 1, wherein the plastic is a fiber-reinforced plastic.22. A closer according to claim 21, wherein the fiber-reinforced plasticis a glass fiber-reinforced or carbon fiber-reinforced plastic.
 23. Acloser according to claim 1, wherein the housing is formed withoutmachining.
 24. A closer according to claim 1, wherein the housingcomprises a plurality of separate adjoining sections fixed together bycementing or welding.
 25. A closer according to claim 1, wherein thehousing comprises a plurality of separate adjoining sections fixedtogether by fastening pins or screws.
 26. A closer according to claim 1,wherein the at least one bore chamber is defined by sections ofadjoining separately made housing parts without machining.
 27. A closeraccording to claim 1, wherein a plurality of parts of said housing aremade of plastic.
 28. A closer according to claim 1, wherein the at leastone bore chamber is closable at least at one end by a separately madeend cap having a margin passing around the at least one bore chamber.29. A closer according to claim 28, wherein the passages are formedwithout machining.
 30. A closer according to claim 29, wherein thepassages lead into the at least one bore chamber.
 31. A closer accordingto claim 1, wherein the recesses are formed without machining orpreformed without machining.
 32. A closer according to claim 31, whereinat least one passage section is open to an end face, a front face, a topface, or a bottom of the housing.
 33. A closer according to claim 31,wherein at least one passage section is a valve passage section.
 34. Acloser according to claim 1, wherein one or more housing parts compriseformed-on, welded-on, or cemented-on mounting feet for fastening to adoor or a door frame, and wherein at least one hole is formed withoutmachining or preformed without machining for receiving a fasteningelement.
 35. A closer according to claim 1, wherein the housingcomprises bores formed without machining that pass through the housingfor fastening screws for fastening to the door or a door frame.
 36. Amethod according to claim 8, wherein assembling the plurality of plastichousing parts comprises cementing or welding.
 37. A method according toclaim 8, wherein forming the at least one bore chamber comprisesassembling at least two housing parts, and wherein each of said at leasttwo housing parts has a cylinder section and is formed as a part cut inthe axial direction of the cylinder or as a part cut transversely of thecylinder, and wherein the at least one bore chamber is a cylinder borefor receiving the damping piston.
 38. A method according to claim 8,wherein the housing is made from fiber-reinforced plastic.
 39. A methodaccording to claim 8, wherein the door closer housing comprises aplurality of bore chambers, wherein one bore chamber is configured as acylinder chamber to receive a piston of the damping device or theclosing spring, and a second bore chamber is configured as a passage ofthe damping device, which is configured as a separate housing passageand leads into the cylinder chamber, and wherein the housing passage ispreformed without machining or at least preformed without machining atleast section-wise during injection molding of the door closer housingwith a mold core.